Fibrous mats, webs and blankets can be made by spinning molten materials like glass, slag, rock and various thermoplastic polymers and copolymers and attenuating the fibers to a desired average or mean diameter with mechanical forces or by jet blasts of air and/or combustion gases. Such processes are disclosed in U.S. Pat. Nos. 4,058,386 and RE030192, the disclosures of which are incorporated herein by reference, and many patents on processes similar to these patents. It is also known to make glass fiber insulation by forming primary fibers and then attenuating the primary fibers into fine insulation fibers using jet blast attenuation as disclosed in U.S. Pat. No. 5,882,372, the disclosure incorporated herein by reference, and in patents covering similar processes. It is also known to produce mat or webs from molten material by passing the molten through orifices, with or without nozzle tips, to form primary fibers and then to attenuate the still soft fibers by mechanically pulling or pulling with one or more rapidly moving gaseous streams to the desired diameters followed by collecting the fibers, wet or dry, onto a moving permeable belt. Also, numerous other systems and methods are known for forming fibrous mats, webs and/or blankets such as those wet or dry systems/methods used to make various kinds of paper, carding and lapping, and inclined wire wet laid nonwoven mat forming. Regardless of the system and method for forming the fibrous mat, web and/or blanket, the products usually contain some portion of very short fibers, fiber chips and other dust which tends fly off of the mat, web and/or blanket products during packaging, un-packaging, further processing, and/or use.
Normally a de-dusting agent is applied to the fibers and attenuated fibers prior to, during or after an aqueous binder is sprayed or otherwise applied onto the fibers prior to collecting the wetted fibers onto a permeable moving belt to form a thin mat, fibrous web or thick fibrous blanket, to reduce the dusting of the fibrous product. The mat, web and/or blanket is then usually passed through an oven, sometimes while being compressed by platens or a moving belt, to dry the product and to cure any binder on the fibers and in the fibrous product. The use of one or more de-dusting agents, applied in coarse particles or coarse droplets to the fibers before collection into an insulation mass is old, e.g. see U.S. Pat. No. 4,134,242, the disclosure incorporated herein by reference.
Fibrous mats are also produced by a process known as dry laid or wet laid processes in which fibers dispersed in air or water are laid onto a moving permeable belt moving over one or more suction boxes to remove the air or water to form a fibrous web. An aqueous binder and de-dusting agents are then applied to the wet or dry fibrous web in conventional ways and, after removing any excess binder and water, the wet, bindered fibrous web is carried through an oven to dry remove the water and to cure the binder in the mat. Such processes are disclosed in (add wet and dry laid mat process patents).
The purpose of the de-dusting agents is to reduce the fly of short fibers and/or dust particles, from the finished product when handling the products during packaging, during opening a bag of compressed product like insulation batts and when installing the products or working with and/or further processing the fibrous products. While the de-dusting agents are effective when present in sufficient amounts, the presence of the de-dusting agents in or on the binder can reduce the effectiveness of the binder, cause more binder to be required to achieve the desired strength in the product. Also, some of the de-dusting agent is volatilized off by the hot air and heat used to increase the temperature of the fibrous product to drive off the water, to dry the product, and particularly due to the high temperature required to cure the binder in the product. A more effective and efficient way of applying the de-dusting oil to the fibrous products is needed.